Mayor John Hickenlooper has raised a heroic amount of private money to help make Denver a better and more hopeful place to live.

For that, he deserves plaudits.

However, amid the $104 million collected, most of it to help poor children go to college and to plant up to 1 million trees, is $150,000 from a secret benefactor to help absorb some of the costs of a prosecutors’ task force to focus on gang violence.

We don’t believe that’s a good approach.

The cloak of anonymity is troubling enough, but the very concept of private funding for city law enforcement services raises troubling questions.

A few City Council members are questioning the money, and rightfully so. The mayor says the money is being funneled through a yet-to-be-named private foundation. Once the check clears, so to speak, Hickenlooper says he’ll identify the foundation, but not the donor. He says he doesn’t know the donors’ names and wants to keep it that way.

“We didn’t want the district attorney or the chief of police to know what individual had given money so there could never be any accusation that this person was avoiding prosecution or this person was getting this or that,” Hickenlooper told The Post. “That’s why we wanted the money to be anonymous.”

Hickenlooper and District Attorney Mitch Morrissey negotiated the deal to help fund a four-person team to investigate and prosecute illegal gang activities. As much as $425,000 is needed over the next 18 months, part of an effort Morrissey proposed to attack gangs with a grand jury investigation.

Secrecy aside, Councilwoman Carol Boigon says accepting the private money could lead to a situation where a defendant can claim he was prosecuted only because he’s an enemy of the benefactor.

“When we are in the position of being able to take away someone’s money, property, freedom and good name, I think it’s very important that we be very, very clear and beyond any remote question that this is truly a public process and not privately funded,” Boigon said.

Just like maintaining city streets, law enforcement is a fundamental responsibility of city government. As such, it should be funded from city coffers.

Morrissey has said the extra money is needed to fill staff gaps that would be created by a redeployment to gang prosecution.

We wonder if it’s not possible for the DA to prosecute gangs within his existing $15 million budget. However, if extra spending is needed , the city should foot the bill. It’s hard to imagine the city wouldn’t be able to find money to fight gangs.